Methods are already known for controlling the position of an actuating element configured as a throttle flap, an exhaust-gas recirculation valve or as a charge movement flap. The position of the actuating element within a displacement range tracks a desired value and the displacement range is limited by at least one stop for the actuating element.
For the position of the actuating element, a digital control is utilized in a motor vehicle which is carried out by the engine control apparatus. For example, the two methods discussed below are used.
In a first method, a sufficiently high scanning rate must be ensured for the control of the position of the actuating element. Here, it must be prevented that the mechanical stops are not driven against in order to avoid damage to the actuating elements. For this purpose, the displacement range is limited with the aid of an offset. For the described systems having high scanning rates, the offset can, as a rule, be selected small because the design of the control can be so selected that only overshoots with low amplitudes occur.
In a second method, the digital control of the position of the actuating element is carried out at a scanning rate, which is less in comparison to the first method, in order to save on running time and the actuating element need not be moved with high dynamic. In this method, a desired value change limit is mostly used. In this way, overshoots are substantially suppressed.